Liquid-tight containers of paper, cardboard or the like carton-forming materials



April 29, 1958 H R [N 2,832,523

ZE L LIQUID-TIGHT CONTAINERS OF PAPER, CARDBOARD OR THE LIKE CARTON-FORMING MATERIALS Filed April 25, 1955 Fig.7

United States Patent G emf:

LIQUID-TIGHT CONTAENERS OF PAPER, CARD- BOARD UR THE LIKE QARTON-FOREHNG MA- TERIALS Hans Zerlin, Dusseldorf, Germany, assignor to Jagenberg- Works AlttaGes, Dusseldorf, Germany Application April 25, 1955, Serial No. 503,558

Claiim priority, application Germany May 28, 1954 4 Claims. (ill. 229--7) The present invention relates broadly to the art of container manufacturing.

More particularly, this invention relates to a liquidtight or leak proof container made of paper, cardboard or the like carton-forming material.

Specifically this invention relates to such a container that is adapted to receive liquid such as milk and which is generally of tubular form having a lower portion that is round and decreases downwardly in cross section and which has closure members secured adjacent the opposite ends.

Single use containers made of paper or cardboard are frequently used for handling liquids such as milk or other materials which must be protected from external influences. Generally such containers are of conical shape whereby nesting and thus a saving in space during storage and shipment is possible. The adaptability for nested relation is of paramount importance since such containers are generally made by conventional paper working machinery and are delivered by the manufacturer to an intermediate user who fills and closes the same and delivers filled containers to the ultimate consumers of the contents.

Containers are known which have an inserted closure for the lower end and a folded upper closure consisting of flaps that are extensions of the container body and which upper closure projects above the level of the liquid filling. Disregarding the additional expenditure in material or labor for forming an extended closure, it is also necessary that this type closure, if it is to be of suflicient tightness, be secured by an additional metal clamp or the like. Moreover such closures generally have a roof-like shape resulting in an unused air-filled space above the level of the liquid contents. It is clear then that such type of folded closure not only precludes piling of filled containers on top of one another and utilizes unnecessary container forming material, it also results in a container in which the total volume is increased without adding to the utility. A further disadvantage resides in the fact that the entrapped air has a detrimental infiuence on the keeping quality of any filling material which is readily spoiled.

In order to avoid the aforementioned deficiencies efforts have been directed to utilize planar closure parts of which the upper closure is disposed in or directly above the plane of the liquid level so that the undesired air space is eliminated and the capacity of the container is utilized to the fullest extent possible. V

In the production of such containers the utilization of a flat bottom closure does not give rise to any particular difiiculties since the association thereof with a container body can be effected while the latter is on a mandrel and which will constitute an effective back up member for the tools that insert the closure and eifect the connection thereof with the container body. By contrast, however, the formation in connection with a top closure creates considerable difliculties, since there is no effective back- 2,332,523 Patented Apr. 29, 1%58 ing up element to resist the pressure applied to the parts to be joined.

Additionally the closing of the upper end of a container by means of a flanged or depending rim type closure does not satisfy the requirements since the rigidity of this type closure and of the upper part of a container body is insufficient to provide the required resistance for the pres sure generated during, connection and sealing of the closure to and with the body. Furthermore, the inverse, that is the insertion of a closure member into a body and which closure member has outwardly directed flanges is unsatisfactory since this closure results in an arrangement in which the plane of the closure lies beneath the upper edge of the container body so that the total volume of the container stands in an unfavorable ratio to its effective capacity.

Accordingly, it is an object of the present invention to provide a container of paper, cardboard or the like cartonforming material in which the formation and closing thereof is effected with the utilization of an absolute minimum amount of material for the top closure while at the same time providing a container body that is of suflicient strength and rigidity as to withstand the closing and sealing pressure when the top closure is applied and in which the volumetric capacity is effectively utilized.

Thus another object of the present invention is to provide an economically produced container which comprises a one piece container body that is longitudinally seamed, has an upper substantially squared mouth, downwardly tapering wall structure that is round in cross-section and of a decreasing diameter, a round bottom closure and a planar substantially squared top closure secured to an outwardly extending rim formed by necking the upper portion of the wall structure.

it is to be further pointed out that the container of the present invention has its lower end closed by a dish like bottom having outwardly extending flanges or a rim that is embraced in U fashion by the lower marginal portion of the container wall structure and joined thereto by adhesive. A bottom closure of this type has the plane of the closure inwardly of the lower marginal edge of the container so that the bottom closure panel does not directly contact any surface that supports the container. Furthermore, a container with this type bottom closure has an enhanced rigidity.

Therefore it is a further object of this invention to provide a container in which the upper end is closed by a planar closure member disposed in the plane of the liquid level and of which the wall structure of the container is necked inwardly toward the axis of the container to provide an outwardly extending rim or lip and in which the perimetrical edge of the rim lies in the plane of the wall structure in that area below the necked in portion and the closure is adhesively secured to the rim or lip.

As a further specific object and in order to provide for uniform distribution of material adjacent the corners of the upper part of the container the cross sectional shape thereof and that of the upper closure part. is in the form of a square having rounded corners. Such shape has a further advantage in that it extensively avoids the risk of damage as is generally attendant to containers of this type having sharply defined corners.

it is a further feature of this invention to provide an arrangement in which the diameter of the round lower closure member corresponds substantially to that of a circle inscribed in the upper and square portion of the container whereby with the marginal edges of the upper closure lying in the plane of the subjacent container wall structure it is possible to stow the containers along side one another substantially without intervening interstices.

As a further feature of this invention, particularly in the manner of joining the upper planar closure to the coordinated underlying rim of the body, there is afforded the possibility of utilizing pressing tools which can exert a sufficient pressure so as to obtain a leak proof conin accordance with the invention,

Figure 2 illustrates the blank utilized in forming the container body,

Figure 3 is a perspective view illustrating the planar upper closure member, Figure 4 is a similar view illustrating the bottom closure member and Figure 5 is a longitudinal cross sectional view through a closed and filled container.

The container of the present invention and as shown in Figure 1 consists of three parts namely, a container body 1, an upper or top closure 2 and a lower or bottom closure 3. The container body 1 is formed from the 'blank shown in Figure 2 and which blank in a known manner is transformed about a shaping mandrel to the form of a body 1 in Figure 1. The blank is shaped so that its bottom edge Sis arcuate and its top edge 6 provided with four straight portions so that when the blank is formed about the mandrel the upper portion or top is generally square in cross section While the bottom is round. This is shown in Figure 1.

Along the bottom edge 8 is a strip of adhesive 9 which is to be utilized in securing the round bottom closure 3 in position. Along the top edge is a strip of adhesive 7 which is to be utilised to secure the top closure 2 in position. Along one side edge 4 is a strip of adhesive 5 which cooperates with the opposite side edge of the blank in forming the longitudinal seam on the container body.

After the container body 1 has been formed into its general shape, the upper portion therein is necked or drawn in toward the axis of the container so as to form the annular groove 10 and to deform the upper edge of the container into the shape of a laterally extending rim or lip. The perimetric edge of this lip lies in the plane of the walls of the container body. Due to the necking in and forming of the lip, the plane of the latter lies substantially in the plane of the closure and thus the outwardly turned lip having the strip of adhesive there on forms What can be termed an abutting surface for the planar closure 2. The undersurface of the rim or lip constitutes an effective receiving .or applying surface that is contacted by the conventional tools utilized during the sealing and pressing step that affects the connection of the top closure 2 with the rim.

As previously indicated the top closure 2 is a planar blank that can be made of the same material as the container body. There is a filling and dispensing opening 11 provided in this blank and as shown in dotted lines in Figure 1 a closure flap 13 is associated with the top of the closure 2 and which closure flap includes a lift up tongue 12.

As also shown in Figure 1 the corners of the upper and generally square end of the container body are rounded off whereby during the formation of the groove 10 by the necking step the material that is at the corners is afforded the possibility of being uniformly distributed without forming excessive accumulation of material in the corners and thus without forming undue overlapping and channels whereby the leak proof characteristics of the container are enhanced.

The lower end of the container is closed by the dish shape closure member 3 shown in Figure 4-. This closure is inserted into the lower end of the container body with its rim 14 directed outwardly of the body following which the lower marginal portion of the container body is rolled around the rim 14 and secured thereto by the cooperation of the adhesive strip 9 with the rim 14.

A container constructed in accordance with the present invention can thus be delivered by the manufacturer in the form of an open ended cup and with the upper and separate planar closure members accompanying the same. The intermediate user can then effect the filling and closing of the container. The container may be filled either before or after the top closure is secured to the lip. Furthermore, during the production of the container, the container structure can be coated with either a synthetic material or with paraflin by an immersion or spraying step in order that the container can be rendered sterile and liquid proof on all its body surfaces. Also the container can be sprayed with paraffin in the manner set forth in prior application 419,442 filed March 29, 1954, now Patent No. 2,801,040 entitled, Liquid-Tight Container of Paper, Cardboard and the Like and Method of Manufacturing, Filling and Closing the Same.

The hinder or adhesive utilized for securing the planar upper closure 2 to the rim at the upper edge of the body is of a type well known in the art that becomes adhesive under the influence of heat and pressure. This of course facilitates the closing of the container by an intermediate user by utilizing the heated, pressing tools.

It is clear therefor that the container of the present invention utilizes an absolute minimum of material in the formation of and securing of the closure to the body while at the same time the closure is horizontally disposed and lies at the upper edge of the containerfbody. Furthermore, the lowerbottom closure is recessed so that the plane thereof does not contact any surface on which the container may be supported. The shape, that is, the upper portion of generally square cross section having rounded corners and with the wall structure tapering downwardly and inwardly and forming a rounded lower portion facilitates stacking and storage of the container while at the same time affording sufficient rigidity.

What is claimed is:

1. A leak proof container of paper, cardboard or th like carton-forming material comprising a container body having at its upper end an approximately square cross section, the walls of the body'closely adjacent the upper end being necked inwards to a depth sufficient to provide an uninterrupted annular groove and an outwardly extending single thickness ledge with the perimetrical edge of-the ledge lying flush with the vertical planes containing the wall structure of the body at its square cross section and a planar closure, having exposed single thick- .ness edges conforming in size and shape to the upper portion of the container as delimited by the perimetrical edge of'the ledge, and said closure being adhesively secured to the ledge with the edges of the closure flush with the edgeof the ledge. g

2. A leak proof container as claimed in claim 1 in which to provide for uniform distribution of material adjacent the corners of the upper part of the container, the upper square portion of the container has highly rounded corners and the' planar closure has highly rounded corners.

3. A leak proof container as claimed in claim 1 in which the lower end of the container is closed by a round bottom closure adhesively secured to the interior of'the lower end of the container, and the diameter of the round bottom closure corresponding substantially to the diameter of a circle inscribed within cross section of the body at the upper part thereof.

4. A leak proof container of paper, cardboard or the like carton-forming material comprising a one piece longitudinally seamed container body having an upper substantially square mouth and an uninterruptedly downwardly gradually tapered wall structure of slightly decreasing cross sectional area terminating in a round bottom, a closure for the bottom having a diameter corresponding substantially to that of a circle inscribed within the mouth, the wall of the container immediately subjacent the mouth being necked inwards to provide an uninterrupted annular groove, and an outwardly projecting peripheral ledge, a layer of adhesive on the upper surface of said ledge, a square planar top closure secured to the upper surface only of the ledge by the adhesive thereon and the perimetrical edges of the top closure and the ledge respectively lying flush with each other and with the exterior of the body immediately subjaeent the groove.

References Cited in the file of this patent UNITED STATES PATENTS Luckett June 11, 1935 Kuchler Aug. 15, 1939 Carroll Oct. 10, 1950 Moifett et al Mar. 31, 1953 Leonard Dec. 1, 1953 Sanford Dec. 29, 1953 Taylor Mar. 9, 1954 Magill Ian. 10, 1956 FOREIGN PATENTS Switzerland Mar. 1, 1933 

